Microsomal and cytosolic cytochrome P450 mediated benzo(a)pyrene hydroxylation inPleurotus pulmonarius

✍ Scribed by S Masaphy; D Levanon; Y Henis; K Venkateswarlu; SL Kelly

• Book ID: 104632508
• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 395 KB
• Volume: 17
• Category: Article
• ISSN: 0141-5492
• DOI: 10.1007/bf00127436

✦ Synopsis

Microsomal and soluble fractions of Hewofus p~rln~o~~a~+rr.s-exhibited a reduced carbon monoxide difference spectrum with P450 maxima at 448nm and 450-452nm respectively. Substrate induced Type I spectra were observed on addition of benzo(a)pyrene to both fractions. Benzo(a)pyrene hydroxylation was measured using the aryl hydrocarbon hydroxylase assay and was observed to be P450 dependent as indicated by carbon monoxide inhibition together with the substrate binding characteristics. The activity of the fractions were observed to give K, of 2OOmM and 660mM and V,, of 1.25 nmol/min/nmol P450 and 0.57 nmol/rnin/nmol P450 for the microsomal and cytosolic fractions respectively.